1. Field of the Invention
This invention generally relates to methods and solutions for processing a substrate and, more specifically, to methods and solutions for preventing the formation of metal particulate defect matter upon a substrate after a plating deposition process.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Unwanted particulate material and byproduct films often accumulate on substrates after plating deposition processes. As such, cleaning processes are often employed to remove the material. In general, the objective of cleaning processes is to provide the plated metal layer with a substantially smooth and planar surface. In addition or alternatively, the cleaning processes may serve to remove metallic particulate material and byproduct films from dielectric materials adjacent to a plated layer such that shorts and leakage current between metallic lines may be mitigated. Cleaning the surface of the dielectric materials may also advantageously increase the surface resistance of the dielectric materials and, as a result, the metallic lines may maintain breakdown voltages within design specifications.
A common technique for removing particulate matter from a substrate after a plating deposition process includes dosing the substrate with copious amounts of water. The technique, however, is generally not effective for removing all particulate matter or preventing the formation of byproduct films. In some cases, acids or strong bases (i.e., having a pH greater than 12.0) have been employed to enhance particulate matter removal after a plating deposition process. Acids and strong bases, however, cause corrosion of metallic films and, thus, such solutions may not be suitable for some applications. For example, as dimensions of integrated circuit components continue to decrease, even the slightest corrosion of a metallic layer or structure during the fabrication of an integrated circuit may become increasingly unacceptable. Furthermore, it has been discovered that metal particles and/or salts may still remain on a surface after applications of acids or strong bases in some cases.
An alternative approach to removing residual matter from a semiconductor surface after a plating deposition process is to apply a solution of hydroxylamine to a semiconductor topography. Similar solutions are used to remove photoresist from a semiconductor topography as well. Although such a technique has been found to be non-corrosive as well as effective for providing surfaces substantially free of particulate material and byproduct films, the use of hydroxylamine is undesirable due to its high cost, lack of availability, and extreme safety issues (e.g., hydroxylamine is prone to exploding upon heating and is an irritant to mucous membranes of humans).
As such, it would be advantageous to develop safe, feasible, cost-effective, and non-corrosive methods and solutions which effectively provide substrate surfaces that are substantially free of particulate material and byproduct films after a plating deposition process.